It seems that with cross-sections, the first step to solving the problem is to cut out the shape to help us visualize the area we are trying to find. Semicircles and squares have different formulas, so visualizing the shape is important for using the right formula. In other words, the cross sections are all about formulas. Where you would fill in variables, you fill in the graph for the line instead. So if I know the formula for unfamiliar shapes, all I have to do is put in the graph for the line in place of variables and I should be good.
If I an't cut out the shapes to help me visualize it, then the best thing to do is probably to keep in mind the shape and put a formula in the top right corner of the page so I won't forget.
This activity was helpful in making me understand volumes of shapes with cross sections because when Mr. Cresswell first said "imagine the image is jutting out from the board", I had absolutely no idea what he was talking about. But having the cutout actually jutting out in front me, I understood that I was to find the area of the cutout.
This might be useful because sometimes, you might have to attach a shape to another shape at a perpendicular angle, but have no idea how big the shape you attach needs to be. In that case, you can use this method to find out. That's just what I can think of off the top of my head.
If I an't cut out the shapes to help me visualize it, then the best thing to do is probably to keep in mind the shape and put a formula in the top right corner of the page so I won't forget.
This activity was helpful in making me understand volumes of shapes with cross sections because when Mr. Cresswell first said "imagine the image is jutting out from the board", I had absolutely no idea what he was talking about. But having the cutout actually jutting out in front me, I understood that I was to find the area of the cutout.
This might be useful because sometimes, you might have to attach a shape to another shape at a perpendicular angle, but have no idea how big the shape you attach needs to be. In that case, you can use this method to find out. That's just what I can think of off the top of my head.